Human umbilical cord blood mesenchymal stem cells differentiate into hepatocypte-like cells: Feasibility of co-culture with human hepatocyte line LO2 in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: Some studies have showed that after indirect co-culture, bone marrow mesenchymal stem cells can differentiate into myocardial cells and hepatocypte-like cells. OBJECTIVE: To investigate the possibility of human umbilical cord blood mesenchymal stem cells (UCB-MSCs) to differentiate into hepatocytes by co-culture with human hepatocyte line LO2 in vitro.METHODS: Full-term umbilical cord blood samples were obtained sterilely. The UCB-MSCs were isolated by density gradient centrifugation and directly adherence growth, then passaged with trypsin digestion at 80% cell fusion. By utilizing cell culture plate insets with microporous membrane combined with 6-well plate, the LO2-/UCB-MSCs co-culture system was established. UCB-MSCs were plated into the wells of 6-well plate at a density of 1×10~7/L. LO2 cells were plated into the cell culture plate insert at a density of 1×10~5/L. UCB-MSCs were plated in both layers in the control group. Surface markers of adhered cells were detected by flow cytometry. Morphological changes of UCB-MSCs were observed by inverted phase contrast microscopy. mRNA expression was detected by reverse transcriptase PCR. RESULTS AND CONCLUSION: HUCB MSCs expressed CD44 and CD29 strongly, but CD34 and CD45 were expressed negatively. After 5 days, fusiform-shaped cells were reduced in the co-culture group; while, the time passing by, cells shaped irregular round or polygonal were increased, which were similar to hepatocytes. At 4 weeks after culture, UCB-MSCs were still fusiform-shaped in the control group. At day 5 after culture, alpha fetoprotein mRNA expressed positively, but other expressed negatively in the co-culture group; at day 14 after culture, cytokeratin-19 mRNA and albumin mRNA expressions were observed; moreover, with the time passing by, the expression of albumin mRNA was increased, but the expression of alpha fetoprotein-19 mRNA was decreased. Antigenic expressions in the control group were negative. This suggested that UCB-MSCs could differentiate into hepatocypte-like cells by co-culture with human hepatocyte line LO2 in vitro.